The APO residency is more than just a welcome stipend and he very much appreciates the enthusiastic and open people in the orchestra's artistic planning department.
"I find myself in a position of trust which I'm not used to," he laughs. "I'm actually asked for my opinion about things, which is cool."
Margetic enjoys taking workshops with younger composers, even though he's "not a person naturally drawn to educational activities".
There has also been preliminary work with the orchestra's chief percussionist, Eric Renick, towards next year's Percussion Concerto. Already, its composer is determined that there will be no racing around the stage, mallets in hand.
"Walking from station to station looks naff," Margetic says. "It disrupts the flow of the music, making what's being played during all the walking around come across as filler."
There's certainly no filler in the seven-minute whirlwind of next week's Mainspring. "It's quite dense and full of notes," is the terse summing-up I'm given, but he also underlines crucial connections with the Carl Nielsen symphony that closes the concert.
A musical fragment from the Dane's second symphony is the mainspring of his piece, inspired, he says, by the little mechanism inside a wound watch that's a source of kinetic energy and makes it run.
Margetic is a great fan of Nielsen, admitting that, as a clarinettist himself, he's inevitably biased when he praises the older man's concerto for the instrument as "the greatest concerto ever written by a human being".
However, there were other factors for this contrapuntal young composer, as it starts with a fugato and that won him over in the first couple of bars.
"It's pretty obligatory for a clarinet player to like Brahms as well," he says, referencing the German's two clarinet sonatas and quintet. "But, from a technical view, I also admire the way that he develops his material.
"Brahms' tight organisation underneath his music provides an architectural support and a feeling of integration and wholeness, even if the listener is not aware of it.
"It's the same with Ligeti," he adds. "Everything is scrupulously organised and sometimes even obviously so, but you don't need to know that to enjoy the music."
What: Auckland Philharmonia Orchestra, Soul of the Cello
Where & when: Auckland Town Hall, Thursday at 8pm